Edwaed kunkleb



3o and in use for the producing of cliches, types,

. UNITED f STATES.

PATENT QFFICE.

EDWARD KUNKLER, OF ST. GALL, AND JACQUES BRUN N ER, OF KDSSNACHT,

ZURICH, SWITZERLAND. I

METHOD OF PREPARING SURFACES FOR PRINTING BY PHOTOGRAPHY.

SPECIFICATION forming part of Letters Patent No. 333,470, dated December29, 1885.

Application filed July 10, 181- 4. Serial No. 137,376. (No model.)Patented in France January 29, 1884, No. 159,994, and in Belgium January29, 1884. No. 63,992.

invented certain new and useful Improvements in the Method of PreparingSurfaces for Printing or. Etching by the aid of Photography; and we dohereby'declare that the following isa full, clear, and exact-descriptiono-f the invention, which will enable others skilled in the art to whichit appertains to make and use the same.

/ In the drawings, Figure 1 represents a 1ongitudinal section, and Fig.2 a cross-section, of an apparatus which we preferably use, ashereinafter stated, in practicing our invention.

The invention relates to an improved process for the manufacture-ofphotographic negative and positive plates, hatched or grained, of glass,paper, card board, or any other suitably transparent or translucentmaterial adapted to the production of types, cliches, or negatives,which can at once in a direct manner be used for the production ofhighly and deeply etched devices on metals, lithographic stone, or othersuitable materials.

1 The methods or processes hitherto known or negatives adapted for theetching on metals, stone, &e., generally require for the true renderingof the photographic. images taken after nature with their middle tones,one or more intermediate manipulations between the photographic negativeandthe ultimate surface in design to be transferred. These methods orprocesses are therefore'wanting in perfect nicety, clearness, orsharpness of contours, shades, and-other details of .the finishedpicture.

In operating according to this invention, by which the grain or hatchingrequired forthe production of high and deep etchings is in most intimatecontact with the surface in def sign or negative or the picture itself,and is,

so to speak, most intimately amalgamated or combined with it; and thisprocess also offers 1 7 5c the further advantage. that the photographici any suitable known way. Then the actinized roo plates made for theabove-mentioned purposes may be treated in the same manner asheretofore, which manner is wellknown to every photographer and amateur,and used for the production of the ordinary photographic negatives,sothat only after the; development of the photographic image-doestheoperation become-a different one from that hitherto generallyknownor. practiced, and the designs or pictures obtained are adapted fordirect trans; mission onto the above-mentioned materials, such asmetals, stone, 85c.

For the making of typographic or other like photographic plates,(negatives and positives) a transparent grained or hatched plate is6111- ployed, and for its production We preferably use bichromatizedgelatine.

When proceeding according to one modifi-' cation or sequenee'of theprocess, we cover polished glass plate on one side with chromegelatine,to which is added more or less of chromekalium ('oichromateofpotash,)according as a coarser or finer grain is wanted. After thedrying of thisprepared plate at a temperature of, say, 80 to 40centigrade, or 86- to 104 Fahrenheit, lower or higher, according to thegrain required, the plate is freely exposed to light during some, say,five to ten minutes, more or less, according to circum stances, and itis then well washed and dried according to the manner usually practicedin this art. After this the grained surface pro du'ced is inked withprinter s ink or suitable composition, and then varnished with negativevarnish. In producing-hatched typographic positive or negative plates,we employ similar photo graphic matrices, types, or cliches, havingthereon the desired hatchings or grainings.

For the production of typographic or such film or layer on the plate,after undergoing suitable drying, is well tanned or hardened, say, bymeans of a concentrated solution of alum, and then subjected to analcohol bath. The gelatinized plates are then covered over with anisolating layer or film of collodion or leather collodion, or collodionprepared with cast0roil,and then treated with an india-rubber, albumen,or other suitable isolating solution. The plate is then dried naturallyor artificially, and is afterward covered again with a layer of, or hasapplied to it, a sensitized solution, gelatine, emulsion, or collodion,and dried or allowed to dry. The plate is then ready for employment inthe photographic art. After the required exposure and subsequentdeveloping and fixing the picture appears on a beautiful underground,presenting the predetermined quality of graining or hatching adapted forthe required end or purpose, and it is thereby rendered thoroughlyadapted for direct high or deep etch- ,ing. The emulsion layer, proof,or film on the glass may be removed therefrom, if so desired, inmannersimilar to that now employed sometimes fora like purpose with theordinary dryplates.

Trade-marks, firm styles or names, and other desired words, ciphers,numbers, or other indication, either by means of a stamp or in any othersuitable manner, may be applied to the margins or other parts of theplates so produced between the first and second emulsion, film, orlayers, which marks, words, numbers, ciphers, &c., then appear after theexposure, development, and fixing of the cliche, type, or negative. Whenproceeding according to a somewhat modified sequence of the operationadapted to the circumstances of an alreadyexisting photographic plate orfilm with the image already upon it, we apply the sensitive film orlayer to the surface of that plate or film and produce thereupon thedesired graining or hatching, as already described.

In the case of a negative or a positive plate or film already bearing apicture or image the surface of which has been already varnished, it isnecessary to remove that varnish, say by means of caustic potash orother suitable solvent therefor, and then having treated that plate orfilm with an insulating film or coating we apply the sensitive layer,and then we hatch or grain this sensitive layer or film in the manneralready set forth herein.

When the grained or hatched negative is desired to be produced of verylarge size and with one sensitive layer for use in effecting thephoto-mechanical transfer of direct photographic takings onto largemetal plates, cylinders, rolls, or drums, for high or deep etching, wefind the following modification to be well adapted to the purpose and togive excellent results: A polished glass plate is covered with a veryfine transparent or diaphanous paper having-upon it the grain orhatching produced by printing. oroth'erwise, I

in such a manner thatv by cutting the said paper along the margins ofthe glass plate such paper may ultimately be removed. This paper,stretched or distended on the glass plate, is isolated by theapplication of a suitable solution-such, for instance, as raw collodionor chrome-alum gelatine or india-rub berand after the drying of thesolution the paper is treated with a sensitive solution of collodion orgelatine emulsion in the usual well-known way. After the photographicexposure, the development, the fixing, washing, and drying of the firstdiaphanous sensitive paper sheet or surface, a second very pure,transparent, or diaphanons paper is pressed onto the finished negativeso that itadheres to that negative. After properly drying, the wholecombined preparation, forming now one sheet or leaf, is separated fromthe glass plate or its equivalent supporting-surface by cutting ordividing it around the edge or margin. The negative or positive beingcovered on both sides by the transparent or diaphanous paper, can becopied from either side without sacrificing its distinctness orsharpness of details, while it is moreover protected from injuriousatmospheric influences.

Such a negative or positive sheet or film as has 3' ust been describedwill be found extremely useful in and adapted to effect the repeatedtransfer of the photographic picture by photomechanical means onto thesurfaces of large plates, drums, rolls, cylinders, or other forms ofmetal for the purpose of high or deep etch= ing'being produced thereonfor printing in colors, calico-printing, or other use. If the purposefor which the sheet so prepared be that of printing in colors fromdesigns or pictures upon the surfaces of cylinders or other forms, suchsheet is,while still aflixed on the glass plate, carefully and evenlycovered or spread over with a thin isolating film of raw collodion, andthen with a thin solution of gelatine applied by means of a sponge, abroad fiat brush,or'other vehicle adapted to the purpose, and is thenallowed to dry freely and thoroughly.

The gelatine solution just referred to has been found well adapted tothis purpose when prepared by the admixture with the gelatine ofone-third part of alcohol and two per centum of alum; but theseproportions may be varied. This gelatine solution having been soapplied, then that portion of the design or picture on the negative orsheet on which it is not desired that the color shall appear is coveredor protected by the application of covering or blockv ing-out ink ormaterial. This application of blocking-out or covering material iseffected before the removal of the sheet from theglass plate .orsupport. After the covering or blocking-out material has become properlydry,.the sheet or film is removed from the glass plate or equivalentsupport, and is applied and secured to the surface to which itsapplication is desired, suchas. to the' surface of a. cylinder.

After the surface, such as that of a cylinder or drum, has been preparedfor the etching for the design for the first color desired the preparedsheet or leaf may be'again used for the production of another similardesign for the like surface of another cylinder or form by stretchingthat prepared sheet or film onto a glass plate or equivalent surface andsecuring it thereon,while the covering or blockingout material is beingremoved by sponging or otherwise with benzine, turpentine, or othersuitable solvent, and then drying the sheet by means of blotting-paperor other suitable absorbent. The design or picture is then again coveredwith coveringcolor or blocking-out material in such a way that only theportions of the design desired for the next color to be printed are leftfree or available for reproduction on the surface to be printed from oretched. The subsequent treatment will then be like that alreadydescribed for the first color surface. The like manipulations may thenbe similarly repeated for any further color portions to be similarlyrepresented by reserved portions'of the design or picture on thesurface, such asa printing cylinder or drum or other form. Thecovering-color or reserving or blockingout matter should be so finelyground or reduced and by admixture with benzine or other suitablesolvent broughtto such a consistency that its most useful power ofattenuation may be secured.

In order to render such large surfaces of sheet so prepared of greaterusefulness it becomesnecessary to afford means of securing them on thesurface whereon the design or picture is to be reproduced wholly or inpart, and for this object the following adaptation or arrangement ofapparatus will be found useful; but in this application we make no claimfor the apparatus, but reserve the right to make an independentapplication therefor. The large negative or positve sheet of transparentmaterial produced as described is wound round or applied to thecylindrical or other contour of the surface desired to be etched indesign, and such sheet having been so applied as lightly and evenly andflatly as possible by the use of the means of retention hereinafterdetailed,not only enables a better result to be attained but alsopermits of its reuse foralarge number of times.

The method of securing the sheets as aforesaid on the surface to whichtheir retention (for the time being) is desired is as follows: Thecylinder or other curved surface is formed hollow, as is representedinthe accompanying drawings, in which Arepresents parts of a printing-drumin section,whiol1 hollow cylindrical form has pierced through it anumber of radial holes, at aa, of smallsize, reaching from the peripheryto the interior of the cylinder, and supplemented, if desired, by twoother rows of small holes disposed in parallel lines or other suitabledisposition,or the number of rows and their disposition may be variedand reaching across the cylinder s surface from side to side-that is tosay, in a direction parallel'to its axial line-or otherwise suitablydisposed. One or both of the axially supportingparts of the rolls ordrums A may be formed hollow or so as to admit of an exhaust beingplaced in communication with the interior of said cylin-v der ordrum-such asapipe from an air pump so as to create a partial vacuum orreduction of pressure therein. One end of thetransparent or preparedsheet or plate is then applied to the cylindrical surface or drum, andthe partial vacuum or reduction of internal pressure'being maintained bythe exhaust, and the drum or cylinder being caused to revolve at asuitable speed,the prepared sheet or a combined film is rolled or spreadaround the drums surface and retained thereon. t

In order further to aid in the better appli; cation of the preparedsurface or combined film bearing the picture or design destined forreproduction on the surface of the cylin-. 4

covered with india-rubber or other suitable elastic material adapted toafford an elastic pressure to the sheet or combined film to be evenlyspread by its agency around surface A.

The operation of the exhaust within the cylinder A is as follows: Thesheet of material described, and carrying the picture, being pressed orspread over the holes pierced through the drum A, the exhaust withinreduces the internal pressure and the external air pressing on theexternal surface of the sheet such sheet becomes fixed or retained tothe surface of the drum so long as the partial vacuum be adequatelymaintained. This period will in most cases be only so long as may bedesirable for the application of the sheet and during the exposure ofthe picture or image on the prepared sheet necessary for its applicationto the drum or cylinders surface, and so soon as the detaching orremoval of the prepared sheet be desired that may readily be effected bythe suspension of the exhaust, when the internal pressure being restoredthe sheet will be separable without its having suffered injury ordeterioration, thus permitting of repeated reuse.

1n referring to hatching or graining, it is to be understood that bysuch term being used no restriction is intended as to the character ofpattern or effect which is referred to, as these will vary greatly withthe nature of the design or picture, and such effects are variouslydenominated as hatching, crosshatching, stippling, graining,mezzotinting, lining, sanding, and other effects of a like nature.

IOO

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. printing by photography, which consists in combining into one plate orsheet two layers of transparent or diaphanous paper, the first or underone of which has the grain or hatching made or printed thereon and isthen covered with a sensitive material, and after exposure anddevelopment applying the other sheet of diaphanous paper pressed ontothe finished negative, the combined sheet being adapted to be copiedfrom either side of the same.

2. The described method of preparing the first or under layer of thesubsequently combined sheet with the desired hatching, marking, orgraining, which consists in providing it with the isolating solution orcomposition, and next the sensitive layer or film thereon, next theexposure, developments, fixing, and other manipulations of the images onthe lower sheet being completed, and then applying the secondtransparent preserving-sheet, so as to

